1. Field of the Invention
The present invention relates in general to air-operated tools and in particular to an angle drive lubricator for a pneumatic rotary tool.
2. Description of the Prior Art
As with all machinery, the proper lubrication of the working parts of a pneumatic rotary tool is a critical design feature. Because such rotary tools are typically small and portable, the lubricating mechanism must be compact so as to fit within the narrow confines of the tool. It is also desirable for the lubricating mechanism to recirculate lubricant within the tool, thereby reducing maintenance requirements.
Early pneumatic tools provided various self-lubricating means. Some, such as U.S. Pat. No. 1,979,007 to Morton, utilize a simple oil reservoir having an outlet for feeding lubricant from the reservoir to the gear teeth. U.S. Pat. No. 1,956,644 to Hamerly discloses an oil regulator for pneumatic tools wherein a cartridge of packed felt or other oil cleaning material is inserted in a passage between the oil reservoir and the air inlet passage of the tool. Compressed air entering the tool passes through the cartridge into the oil reservoir creating pressure on the oil therein and, at the same time, removing any dirt or other foreign matter collected on the cartridge. When the pressurized air is removed from the tool, the air travels in the opposite direction from the reservoir carrying oil with it through the cartridge and into the motor section of the tool to lubricate the parts.
U.S. Pat. No. 3,719,254 to Snider discloses a lubricated angle drive attachment for an air-operated tool. An output shaft is surrounded by a housing which is hollow so as to constitute a lubricant reservoir. A sleeve of absorbent material is disposed within the housing for rotation with the output shaft. Lubricant is centrifugally thrown onto the gears as the output shaft and the absorbent sleeve rotate. Lubricant is thus supplied directly onto the teeth of a bevel gear and into the zone of intermesh between the gears and a bevel pinion.